1. Field of the Invention
The present invention relates generally to a crawler pad. More specifically, the invention relates to a crawler pad to be fitted on the tread side of crawler plates of a dry field crawler to be employed in a caterpillar type vehicle, such as a bulldozer, shoveldozer, power-shovel and so forth.
2. Description of the Related Art
Conventionally, for the purpose of protection of a road surface from a crawler, pads are fitted on the tread side of respective crawler plates forming a crawler.
Japanese Unexamined Utility Model Publication (Kokai) No. 3-24485 discloses a typical example of such type of crawler pads.
The conventional crawler pad is illustrated in FIG. 71. As shown, the conventional crawler pad comprises a pad body A formed of a hard rubber material into an essentially rectangular cross-section and hooking members c, c removably secured on longitudinal ends of the pad body a by means of fastening members, such as fastener bolts b, which hooking members c, c are adapted to engage with the edges of the crawler plate. The pad body A is formed with a groove d for engaging with a grouser of the crawler plate on the bottom surface thereof. The crawler pad is mounted on the crawler plate with engaging the groove d with the grouser of the crawler plate and engaging the hooking members c, c with the edges of the crawler plate so that the crawler pad will not cause displacing during traveling of the vehicle.
However, in the conventional crawler pad as set forth above, since the fastening bolts for securing the hooking members onto the pad body project from both sides of the pad, they may contact with bump or other matters on the traveling path to damage the bolts per se as well as the hooking members to loose off.
Also, in the prior art, since prevention of displacement of the pad relative to the crawler plate in the running direction of the crawler is realized by engaging the groove d formed in the pad body a with the grouser of the crawler plate, it is not applicable for the crawler plate having the grouser at an appropriate position, such as the intermediate position in the running direction of the crawler plate or for the crawler plate having relatively high grouser, such as for bulldozer crawler plate for dry ground. This limits applicable models of the vehicles.
Furthermore, the conventional crawler pad is formed into a solid block of hard rubber in overall thickness while a metal core insert is provided so that the back side thereof will directly contact with the tread surface of the crawler plate. This clearly requires relatively large amount of hard rubber to result in high cost.
In addition, since the allowable wearing of the pad body is limited to the equal height to the height of the hooking members c, c, the remaining rubber pad after wearing up to the allowable limit has been simply disposed. Since the hard rubber is relatively expensive, disposing of worn pad body is wasteful.
Also, in the prior art, since a reinforcement, such as the metal core, is inserted within the hard rubber, it is difficult to remove the metal core for recycling upon disposing the rubber pad. Furthermore, the presence of the metal core in the disposed pad makes the disposing process difficult.
As set forth above, in the prior art, the crawler pad is mounted on the crawler plate by means of the hooking members c, c at both ends. This requires installation of the hooking members c, c for respective sides of the crawler pads to degrade workability.